Q.2 a. Discuss the OSI protocol architecture in detail ... · PDF fileregarding the structure...

DC70 NETWORK MANAGEMENT DEC 2015

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Q.2 a. Discuss the OSI protocol architecture in detail. List out, at least one salient service provided by each layer (8)

Answer:


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b. Identify the various network management functions and the groups that

perform these functions. Also, explain the interactions among these groups. (8)

Answer:


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Q.3 a. Compare the two-tier network management organizational model with the

three-tier network management organizational model. Illustrate your answers with suitable diagrams (8)

Answer: In the two-tier model network objects consist of network elements such as hosts, hubs, bridges, routers and so on. They can be classified into managed and unmanaged objects or elements. The managed elements have a management process running in them called an agent , which is not present in the unmanaged objects.The managed element is managed by a manager. There is a database present in the manager. The manager queries the agent and receives the management data, processes and stores it in its database. The agent can also send a minimal set of alarm information to the manager unsolicited.

Diagram on p133

2- marks for explanation and 2 marks for diagram

However in a three tier configuration, the intermediate layer acts as both agent and manager. As manager , it collects data from the network elements , processes it and stores the result in it database. As agent it transmits information to th top-level manager. Diagram on p134

2- marks for explanation and 2 marks for diagram


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b. What is ASN.I and why is it required? With the help of a block diagram , outline the ASN.I data type structure and tag (8)

Answer: For communication among systems, it is important that a formalized set of rules be agreed upon regarding the structure and meaning of language of communication, that is the syntax and semantics of the language . Because of the variety of sets of application and transport protocols, it is better to choose a syntactical format of language that specifies the management protocol in the application layer , which is transparent to the rest of the protocol layer . A proven format is Abstract syntax Notation One, ASN.1. It is a formal language developed jointly by CCITT and ISO fro use with application layers for data transfer between systems. It is also applicable within the system for clearly separating the abstract syntax and the transfer syntax at the presentation layer.

1 for what is ASN.1, 2 marks for why it is needed and 5 for block diagram(p150) Q.4 a. Explain, with the help of a block diagram, a Proxy Server Organization

model. List and explain the five protocol messages of SNMPv1 which facilitate the communication of management information among management entities (8)

Answer: P 180 – the Proxy Server Organization Model.(3 marks) 5 marks for the messages.

The get-request message is generated by the management process requesting the value of an object. The value of an object is a scalar variable.

The get-next-request is similar to get-request message .An object may have multiple values because of the multiple instances of the object.. This message obtains the value of the next instance of the object.

The set-request message is generated by the management process to initilaize or reset the value of an object variable.

The get-response message is generated by an agent process. It is generated only on receipt of a get-request, get-next-request or set-request message from a management process. The get-response process involves filling the value of the requested object with any success or error message associated with the response

The other message that the agent generates is trap. A trap is an unsolicited message generated by an agent process without a message or event arriving from the management process. A trap occurs when the agent observes the occurrence of a preset parameter in the agent module.

b. What are the following data types of SNMP ASN.I used for? Also specify the structure of each of the data type.

(i) Gauge (ii) Time-ticks (iii) Opaque (iv) SEQUENCE (8)


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Answer: i. Gauge- is used a non-negative integer,its value can move either up or down. It is used for

data types whose value increases or decreases, such as the number of interfaces that are active in a router or hub. It is a defined data type.

ii. Time-ticks- is a non-negative integer and measures time in units of hundredths of a second. Its value value indicates in hundredths of a second the number of units of time between the current instant and the time it was initialized to 0.It is a defined data type.

iii. Opaque- is an application –wide data type that supports the capability to pass arbitrary ASN.1 syntax.It is used to create data types based on previously defined data types. When it is encoded, it is double wrapped,meaning te TLV for the new definition is wrapped around the tLV of the previously defined type.

iv. SEQUENCE- is a constructor data type. It is used to build a list. Q.5 a. What are protocol entities? How is communication among these protocol

entities is accomplished? Show the structure of encapsulated SNMP message. (8)

Answer: The peer processes which implement the SNMP, and thus support the SNMP application entities, are called protocol entities. Communication among protocol entities is accomplished using messages encapsulated in UDP datagrams.(1+1)

Explanation of message + diagram of message (6) p 234

b. What is Remote Monitoring? Discuss its advantages. (8) Answer:


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Q.6 a. What is a protocol analyzer? Explain the basic configuration used for a

protocol analyzer. Use suitable diagram. Name any two popular commercial protocol analyzers. (8)

Answer: The protocol analyser is a powerful and versatile network management tool. It analyzes data packets on any transmission line.It is primarily used in LAN environment. Protocol analyzer measurements can be made either locally or remotely.(2 marks)

The basic configuration :: - diagram p 498 ( 2 marks)

It consists of a data capture device that is attached to a LAN and can be a specialized tool; it can also be a personal computer or workstation with a network interface card. The captured data are


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transmitted to the protocol analyzer via a dial-up modem connection,a LAN or campus network or a WAN. The protocol analyzer analyzes the data and presents the results to the user on a user-friendly interface.(2 marks)

Two popular analyzers – Sniffer, NetMetrix (2 marks) b. Identify the five functional components of a Network management system.

List any one service offered by each of these components along with pictorial representation. (8)

Answer: The five functional components are

Component Service

i. Hardware – Processor ii. Operating system- OS service

iii. Core application service – Display/GUI iv. Common SNMP services- SNMPv1 messages / SNMPv2 messages v. Vendor –specific NMS services- MIBmanagement

Diagram – p 506 (1/2 marks for identifying component + ½ mark for nay service)

(3 marks for diagram)

Q.7 a. What is a fault? Explain the various steps in fault management. Name any two methods of fault detection. (8)

Answer: Fault in a network is normally associated with failure of a network component and subsequent loss of connectivity.(1 mark) Fault management process is a five step process

i. Fault detection – The fault should be deteted as quickly as possible by the centralized management system , preferably before or at about the same time as users would notice it.

ii. Fault location- involves identifying here the problem has occurred iii. Service restoration- has a higher priority than diagnosing the problem and fixing it iv. Identification of the problem – identifying the root cause, can be a complex process v. Problem resolution – After source of problem is identified , a trouble ticket is generated.

In an automated network , this ticket could be generated automatically by the NMS.(5 marks)

Fault detection is accomplished by using either a polling scheme or generation of traps(2 marks)

b. Differentiate between secret key cryptography and public key cryptography. (8) Answer:


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Q.8 a. What is the function of planning and management reports in report

management activity of network management? List the various categories of the planning and management reports with an example from each of the category (8)

Answer: Planning and management reports keep upper management apprised of status of network and system operations. They also help in planning and budgeting the capital and operational expenses.(2 marks)

Categories and example, p 575 (1 mark for each category and ½ mark for example) b. What is Service level management? Identify the characteristics associated

with services (8) Answer: Service level management is defined as the process of

i. Identifying services and characteristics associated with them ii. Negotiating a service level agreement

iii. Deploying agents to monitor and control network, system and application component performance and

iv. Producing service level reports ( 4 marks) Characteristics associated with services are

i. service parameters ii. Service levels

iii. Component parameters iv. Component-to-service mappings ( 4 marks)

Q.9 a. What is Windows Management Instrumentation (WMI)? Explain the WMI architecture in detail, with the help of an example. (8)

Answer: WMI is the infrastructure implemented by Microsoft to support the WBEM CIM

and Microsoft –specific extensions to it.


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P596, 597 b. What is Embedded Web-based management? What are the benefits of

Embedded Web-based management? (8) Answer:

Q.2 a. Discuss the OSI protocol architecture in detail ... · PDF fileregarding the structure...

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